Physiological and clinical effects of two ultraprotective ventilation strategies in patients with veno-venous extracorporeal membrane oxygenation: the ECMOVENT study

Annals of Intensive Care volume 15, Article number: 111, Published: 01 August 2025

Purpose

The optimal ventilation strategy in acute respiratory distress syndrome (ARDS) patients with veno-venous extracorporeal membrane oxygenation (VV-ECMO) remains unknown. We aimed to compare the effects of two ultra-protective ventilatory strategies applied to patients with ARDS and VV-ECMO.

Methods

Our study was an observational, retrospective, single-center study with a before-and-after design. All consecutive patients treated with VV-ECMO for severe ARDS between 2016 and 2023 were included. Before 2021, patients received a quasi-apneic ventilation strategy in assist-controlled volume mode with a tidal volume (V_T) of 1 ml.kg⁻¹ predicted body weight (PBW), a respiratory rate (RR) of 5 min⁻¹ and a PEEP set to keep plateau pressure (P_PLAT) between 20 and 25 cmH₂O. From 2021 onwards, the protocolized ventilatory strategy consisted in pressure-controlled mode with a PEEP of 14 cmH₂O, a driving pressure (∆P) of 8 cmH₂O and a RR of 10 min⁻¹. We evaluated the impact of strategies on longitudinal respiratory mechanics and on the time to successful ECMO weaning at day-90 after VV-ECMO canulation.

Results

121 patients were enrolled, with 69 receiving the VT1 strategy, and 52 the ∆P8 strategy. Over the first 7 days of ECMO, the ∆P8 strategy was associated with significantly higher ∆P and RR, lower PaCO₂, and higher static elastic mechanical power, compared with the VT1 strategy. The day-90 survival rate was 30% with the VT1 strategy, and 42% with the ∆P8 strategy (P = 0.19). Time to successful VV-ECMO weaning was 7 [4–13] days in day-90 survivors, with no significant difference between groups. The adjusted subdistribution hazard ratio associated with the ∆P8 strategy was 0.99 (95% confidence interval: 0.53–1.84), as compared to the VT1 strategy (P > 0.9).

Conclusions

In the context of our center, a ventilatory strategy targeting a PEEP of 14 cmH₂O, a ∆P of 8 cmH₂O and a RR of 10 min⁻¹ led to the application of ∆P, RR and static elastic mechanical power and improved decarboxylation, compared to a strategy in volumetric mode with a V_T of 1 ml.kg⁻¹ PBW and a RR of 5 min⁻¹, in patients with ARDS and VV-ECMO. No significant difference on clinical outcomes was observed between both strategies.

 

Effects of prone positioning on lung mechanical power components in patients with acute respiratory distress syndrome: a physiologic study

 

by Christoph Boesing, Joerg Krebs, Alice Marguerite Conrad, Matthias Otto, Grietje Beck, Manfred Thiel, Patricia R. M. Rocco, Thomas Luecke and Laura Schaefer 

 

Critical Care volume 28, Article number: 82 (2024) Published: 15 March 2024

 

Background

Prone positioning (PP) homogenizes ventilation distribution and may limit ventilator-induced lung injury (VILI) in patients with moderate to severe acute respiratory distress syndrome (ARDS). The static and dynamic components of ventilation that may cause VILI have been aggregated in mechanical power, considered a unifying driver of VILI. PP may affect mechanical power components differently due to changes in respiratory mechanics; however, the effects of PP on lung mechanical power components are unclear. This study aimed to compare the following parameters during supine positioning (SP) and PP: lung total elastic power and its components (elastic static power and elastic dynamic power) and these variables normalized to end-expiratory lung volume (EELV).

Methods

This prospective physiologic study included 55 patients with moderate to severe ARDS. Lung total elastic power and its static and dynamic components were compared during SP and PP using an esophageal pressure-guided ventilation strategy. In SP, the esophageal pressure-guided ventilation strategy was further compared with an oxygenation-guided ventilation strategy defined as baseline SP. The primary endpoint was the effect of PP on lung total elastic power non-normalized and normalized to EELV. Secondary endpoints were the effects of PP and ventilation strategies on lung elastic static and dynamic power components non-normalized and normalized to EELV, respiratory mechanics, gas exchange, and hemodynamic parameters.

Results

Lung total elastic power (median [interquartile range]) was lower during PP compared with SP (6.7 [4.9–10.6] versus 11.0 [6.6–14.8] J/min; P < 0.001) non-normalized and normalized to EELV (3.2 [2.1–5.0] versus 5.3 [3.3–7.5] J/min/L; P < 0.001). Comparing PP with SP, transpulmonary pressures and EELV did not significantly differ despite lower positive end-expiratory pressure and plateau airway pressure, thereby reducing non-normalized and normalized lung elastic static power in PP. PP improved gas exchange, cardiac output, and increased oxygen delivery compared with SP.

Conclusions

In patients with moderate to severe ARDS, PP reduced lung total elastic and elastic static power compared with SP regardless of EELV normalization because comparable transpulmonary pressures and EELV were achieved at lower airway pressures. This resulted in improved gas exchange, hemodynamics, and oxygen delivery.

 

Mechanical power of ventilation and driving pressure: two undervalued parameters for pre extracorporeal membrane oxygenation ventilation and during daily management?

by K. Hoppe, E. Khan, P. Meybohm and T. Riese 

Critical Care volume 27, Article number: 111 (2023) Published: 14 March 2023

Abstract

The current ARDS guidelines highly recommend lung protective ventilation which include plateau pressure (Pplat < 30 cm H2O), positive end expiratory pressure (PEEP > 5 cm H2O) and tidal volume (Vt of 6 ml/kg) of predicted body weight. In contrast, the ELSO guidelines suggest the evaluation of an indication of veno-venous extracorporeal membrane oxygenation (ECMO) due to hypoxemic or hypercapnic respiratory failure or as bridge to lung transplantation. Finally, these recommendations remain a wide range of scope of interpretation. However, particularly patients with moderate-severe to severe ARDS might benefit from strict adherence to lung protective ventilation strategies. Subsequently, we discuss whether extended physiological ventilation parameter analysis might be relevant for indication of ECMO support and can be implemented during the daily routine evaluation of ARDS patients. Particularly, this viewpoint focus on driving pressure and mechanical power.

Critical Care Bulletin - January 2022

 

Mechanical power in pediatric acute respiratory distress syndrome: a PARDIE study

 

by Anoopindar K. Bhalla, Margaret J. Klein, Vicent Modesto I Alapont, Guillaume Emeriaud, Martin C. J. Kneyber, Alberto Medina, Pablo Cruces, Franco Diaz, Muneyuki Takeuchi, Aline B. Maddux, Peter M. Mourani, Cristina Camilo, Benjamin R. White, Nadir Yehya, John Pappachan, Matteo Di Nardo

Critical Care volume 26, Article number: 2 (2022) Published: 03 January 2022

Background

Mechanical power is a composite variable for energy transmitted to the respiratory system over time that may better capture risk for ventilator-induced lung injury than individual ventilator management components. We sought to evaluate if mechanical ventilation management with a high mechanical power is associated with fewer ventilator-free days (VFD) in children with pediatric acute respiratory distress syndrome (PARDS).

Methods

Retrospective analysis of a prospective observational international cohort study.

Results

There were 306 children from 55 pediatric intensive care units included. High mechanical power was associated with younger age, higher oxygenation index, a comorbid condition of bronchopulmonary dysplasia, higher tidal volume, higher delta pressure (peak inspiratory pressure—positive end-expiratory pressure), and higher respiratory rate. Higher mechanical power was associated with fewer 28-day VFD after controlling for confounding variables (per 0.1 J·min−1·Kg−1 Subdistribution Hazard Ratio (SHR) 0.93 (0.87, 0.98), p = 0.013). Higher mechanical power was not associated with higher intensive care unit mortality in multivariable analysis in the entire cohort (per 0.1 J·min−1·Kg−1 OR 1.12 [0.94, 1.32], p = 0.20). But was associated with higher mortality when excluding children who died due to neurologic reasons (per 0.1 J·min−1·Kg−1 OR 1.22 [1.01, 1.46], p = 0.036). In subgroup analyses by age, the association between higher mechanical power and fewer 28-day VFD remained only in children < 2-years-old (per 0.1 J·min−1·Kg−1 SHR 0.89 (0.82, 0.96), p = 0.005). Younger children were managed with lower tidal volume, higher delta pressure, higher respiratory rate, lower positive end-expiratory pressure, and higher PCO2 than older children. No individual ventilator management component mediated the effect of mechanical power on 28-day VFD.

Conclusions

Higher mechanical power is associated with fewer 28-day VFDs in children with PARDS. This association is strongest in children < 2-years-old in whom there are notable differences in mechanical ventilation management. While further validation is needed, these data highlight that ventilator management is associated with outcome in children with PARDS, and there may be subgroups of children with higher potential benefit from strategies to improve lung-protective ventilation.

Take Home Message: Higher mechanical power is associated with fewer 28-day ventilator-free days in children with pediatric acute respiratory distress syndrome. This association is strongest in children <2-years-old in whom there are notable differences in mechanical ventilation management.